Keywords:high-k, SiGe, interface trap density
SiGe MOSFETs have stirred much attention as pchannel devices, because of the high hole mobility and the appropriate bandgap. However, the undesired formation of GeOx in the interfacial layers (IL) can be regarded as an origin of the MOS interface degradation . We have recently reported the improvement of SiGe MOS interface properties by employing TiN/ALD Y2O3 gate stacks with PMA at 450oC , whereas the effects of different high-k films on the SiGe MOS interface properties have not been fully studied yet. In this study, the impacts of ALD high-k materials, Y2O3, Al2O3, HfO2 and ZrO2, on the SiGe MOS interface properties including Dit are systematically examined with changing PMA temperature.